1. Field of the Invention
The present invention relates to a tool attachment system for construction or demolition equipment which is adapted to be attached to a backhoe for attaching multiple tools, such as a heavy-duty metal cutting shear, a plate shear, a concrete crusher, a grapple or the like. More particularly, the present invention relates to a multiple tool attachment system for attaching tools having plural movable jaws.
2. Description of Related Art
The present application refers to demolition equipment; however, the equipment is also referred to as construction equipment, scrap handling equipment and the like. The description of demolition equipment or construction equipment is not intended to be restrictive of the equipment being referenced. Demolition equipment, such as heavy-duty metal cutting shears, grapples and concrete crushers, has been mounted on backhoes powered by hydraulic cylinders for a variety of jobs in the demolition field. This equipment provides for the efficient cutting and handling of scrap. For example, in the dismantling of an industrial building, metal scrap in the form of various diameter pipes, structural I-beams, channels, angles, sheet metal plates and the like, must be efficiently severed and handled by heavy-duty metal shears. Such shears can also be utilized for reducing automobiles, truck frames, railroad cars and the like. The shears must be able to move and cut the metal scrap pieces regardless of the size or shape of the individual scrap pieces and without any significant damage to the shears. In the demolition of an industrial building, concrete crushing devices, such as a concrete pulverizer or concrete crackers, are also used to reduce the structure to manageable components which can be easily handled and removed from the site. Wood shears and plate shears also represent specialized cutting devices useful in particular demolition or debris removal situations depending on the type of scrap. Also, a grapple is often utilized where handling of debris or work pieces is a primary function of the equipment. Historically, all of these pieces of equipment represent distinct tools having significant independent capital cost. Consequently, the demolition industry has tended to develop one type of tool that can have the greatest possible utility and application.
With regard to metal shears, one type of known shear is a shear having a fixed blade and a movable blade pivoted thereto. The movable blade is pivoted by a hydraulic cylinder to provide a shearing action between the blades for severing the work pieces. Examples of this type of shear can be found in my prior U.S. Pat. Nos. 4,403,431; 4,670,983; 4,897,921; 5,926,958; and 5,940,971, which are incorporated herein by reference.
The prior art has also developed a variety of demolition tools utilizing a plurality of movable jaws. U.S. Reissue Pat. No. 35,432 and U.S. Pat. No. 5,060,378 both disclose heavy-duty metal cutting shears having a body and a pair of movable jaws mounted to the frame for pivoting about a common point. Each jaw includes a plurality of cutting inserts in shearing relation with the inserts on the other jaw, with one jaw forming a slot for maintaining the inserts in shearing relation to each other throughout the cutting movement. Each jaw is operated by an independent hydraulic cylinder. The jaw configuration provides a hook-shaped structure with one of the jaws having a cutting or piercing tip at the end thereof. However, these patents do not optimize the jaw structure for the purpose of cutting. Additionally, the independent cylinders increase the cost and prevent a compact shear design.
U.S. Pat. No. 5,359,775 discloses a metal cutting shear with a pair of movable jaws pivotally mounted to a frame with a pair of jaws operated off of a common piston extending between the jaws.
U.S. Pat. Nos. 4,838,493; 4,890,798; 5,044,569; 5,636,802; and 5,738,289 all disclose a variety of concrete crushers having a plurality of movable jaws operated through hydraulic cylinders. U.S. Pat. Nos. 4,903,408; 5,044,568; 5,199,658; 5,243,761; and 5,626,301 also disclose a variety of demolition equipment having a plurality of movable jaws.
The prior art does not provide a system for easily changing tools or a system which allows complete separate tools to efficiently share a common structure. Further, the prior art fails to optimize the jaw structure utilized in the individual tools, such as metal cutting shears, to maximize power and efficiency. Additionally, the prior art provides a complex arrangement for rotations of the tool and jaws without sufficient protection for any hydraulic cylinder powering the working jaws.